Field of the Invention
The present invention relates to a focal-plane shutter and an optical apparatus.
Background Art
An optical apparatus, for example, a digital camera and a still camera, employs a focal-plane shutter. In the operation of the focal-plane shutter, a curtain including a front curtain and a rear curtain is moved between an open position where an opening of a substrate is open and a closed position where the opening is closed. The focal-plane shutter includes a cushioning member that comes into contact with the curtain in a curtain movement end position to stop the curtain. The cushioning member, which comes into contact with the curtain in the curtain movement end position, reduces the impact produced when the curtain moving at high speed stops.
For example, a blade drive apparatus (focal-plane shutter) described in JP-A-2011-170226 includes a substrate having an opening, a blade that moves between a position where the blade retracts from the opening and a position where the blade overlaps with at least part of the opening, and a cushioning member that has a loop-like shape, has elasticity, comes into contact with the blade at an end of the blade movement range, and is so deformable that the loop-like shape is distorted when the cushioning member comes into contact with the blade.
JP-A-2011-170226 states that the blade drive apparatus can suppress a bounce of the blade that occurs when the blade comes into contact with the cushioning member.
When the curtain and the cushioning member come into contact with each other, foreign matter may be produced in some cases due to peel-off of a film coated on the curtain or wear of the cushioning member. When the foreign matter intrudes into the opening of the substrate, the quality of a captured image could undesirably deteriorate.